1. Field of the Invention
This invention relates to an automobile transmission control arrangement and covers an improvement in the mechanism and control arrangement of application Ser. No. 647,603.
2. Summary of the Prior Art
The mechanism of the earlier application comprises a drive shaft, an input shaft of a change-speed gear, an output shaft for connection to the road wheels, a coupling device connecting the drive shaft and the input shaft of the change-speed gear, a reversing gear connecting an output shaft of the change-speed gear to the output shaft of the transmission, means for actuating a brake of the input shaft and means for selecting manually positions for "forward drive" or "reverse drive", and positions "neutral" and "parking brake" of the reversing gear by means of a linkage comprising a manual control lever. Again in accordance with application Ser. No. 647,603, the actuating means are constituted by a supply circuit for providing brake pressure fluid, in which is incorporated a solenoid valve normally interrupting this circuit when it is not energized and of which the electrical energizing circuit comprises at least one normally open switch movable to its closed position by the lever. The linkage comprises a resilient device capable of being compressed, when the applied control force on the lever reaches a predetermined value. According to one of the characteristics of the present invention, the switch is provided with a closure member constituted by a self latching relay of which the energizing circuit is closed by means co-operating with the lever, when the latter is operated to establish a connection between the input and output shafts of the reversing device.
According to a preferred construction, the means co-operating with the lever comprise a first pair of contacts in a first branch, termed a holding branch of the energization circuit of the said relay, capable of being interrupted by the said switch, which contacts co-operate with the lever so as to be open only when the lever is in one of the four positions "forward drive", "reverse drive", "neutral" and "parking brake", and by a second pair of contacts in a second branch of the energization circuit of the said relay, termed the starting branch, connected in parallel with the first holding branch at the terminals of the switch, the second contact pair co-operating with the lever so as to be closed only when the lever is moved in the sense of establishing, in connection with the reversing device, a connection between the input and output shafts of the reversing device.